Three-dimensional (3D) printing refers to the process of creating a 3D object through an additive process, where successive layers of material are laid down under the control of a computer. Conventionally, a three-dimensional printer can use an extrusion 3D printing process, which refers to a Fused Deposition Modeling (FDM) process or a similar process where a build material is heated and then deposited layer by layer onto a build platform. By adding many thin layers on top of one another, sometimes hundreds or thousands, a 3D object is created.
Typically, 3D printers include at least one printer head, or extruder, containing a nozzle from which the melted build material is extruded onto the build platform to create 3D objects. The build material generally originates from an upstream feed of a raw polymer in the form of a filament. This filament is fed into the upper region of the extruder as a solid, where it is then melted and deposited in its molten form from the extruder nozzle in a continuous stream.